A cellular power amplifier may have a relatively low output impedance of, e.g., 3 Ohms. Typically, this output impedance is transformed to an antenna impedance of, e.g., 50 Ohms, with a lumped-element inductor-capacitor (L-C) low-pass matching network. These matching networks are typically large and can be associated with significant insertion losses. Furthermore, they may work satisfactorily only over a limited bandwidth.
Increasingly, cellular phones operate in multiple modes and across a wider range of frequencies. Also, efficiency improvements and size reductions are constantly being sought for radio frequency functions within the cellular phones, so that additional customer services may be added without compromising usability.